In an effort to reduce utility costs and energy use, homeowners and building owners around the world seek to reduce heat loss during winter, and air conditioning loads during summer months. In addition to providing thermal insulation to reduce conductive heat loss, an important factor in controlling and maintaining temperature within a building is the reduction of outside air infiltration. Numerous measures are taken to reduce air infiltration such as the use of building wraps and new window and door technologies designed to reduce air leakage. Another point of air infiltration is electrical outlets which are mounted in penetrations through building interior wall boards of perimeter walls. The openings provided for electrical outlets in such walls represent a pathway for air infiltration. It is known to use foam type gaskets underneath an electrical outlet cover plate to help reduce air infiltration. However, even when such gaskets are used, there remains a gap around the electrical outlet socket as well as through the electrical outlet socket openings themselves. This invention provides a system and a kit which effectively reduces air infiltration through the pathways mentioned previously.